Study investigates sea turtle strandings

Understanding the causes of sea turtle strandings and deaths along the Mid North Coast is the aim of a new research project by Southern Cross University marine science student Tegan Baker.

Tegan, who is completing her Honours year in the Bachelor of Marine Science at the University’s National Marine Science Centre, is working closely with veterinarian Duan March, from Dolphin Marine Magic and supervisor Dr Sander Scheffers, from the University’s School of Environment, Science and Engineering.

The project, which will also look at the spatial distribution of sea turtles, is the first of its kind in the region.

“I am looking at the causes of stranding and mortality of sea turtles from Yamba in the north to Old Bar, near Taree, in the south,” Tegan said.

“When a turtle strands it usually means they are injured, sick or exhausted. The only other time a turtle will come out of the sea is if it’s a female coming to lay her eggs.

“We have got five years of data, with 205 recorded turtle strandings along this part of the coast. There seems to be a seasonal trend, with more strandings in October, November and December.

“Some of the turtles have obviously become entangled in fishing lines or been injured as a result of a boat strike, but for the vast majority of strandings there are no obvious injuries.”

Using samples provided by Dr March, Tegan is assessing the concentration of heavy metals in tissue from sea turtles that have stranded but not survived.

The three locations with the highest number of strandings are Minnie Water, Brooms Head and Coffs Harbour.

Tegan said one of the challenges was the lack of baseline information.

“What I am really hoping is that as a result of my study we will gain a better understanding of why these animals are stranding and with that, we may be able to do something to improve the situation,” she said.

Dr March said sea turtles were considered as one of the longest living vertebrates, and took approximately 30 to 50 years to reach maturity.

“Of the seven species of sea turtle, six have been recorded on the NSW coastline and all are listed as threatened species. The concerning thing about these strandings is we don’t know why they are occurring – all of our investigations so far have drawn a blank, so hopefully Tegan has some luck with this investigation,” Dr March said.

The study has been supported by a $500 contribution from the Coffs Harbour Animal Rescue Trust (CHART), which has been created by Dolphin Marine Magic (DMM) to facilitate the rescue, research and rehabilitation of wildlife in the Coffs Harbour region.

Dr March said the trust had a strong focus on marine wildlife and koalas, given the prevalence of disease issues these species faced in this area. The trust aims to construct a wildlife hospital in the region, however the focus in the short term was providing financial and in kind support to local wildlife and conservation projects.

The project is expected to be completed by the middle of the year.

Photo: Tegan Baker and Dr Duan March take measurements of a green turtle, being rehabilitated at Dolphin Marine Magic in Coffs Harbour.